Integrins play a role in stress relaxation of perivascular adipose tissue.

Perivascular adipose tissue (PVAT) is known for being anti-contractile in healthy tissues. We discovered a new function of PVAT, the ability to stress relax and maintain a tone in response to a stretch. This is of note because stress relaxation has been attributed to smooth muscle, of which PVAT has none that is organized in a functional layer. We test the hypothesis the interactions of integrins with collagen play a role in stress relaxation. Our model is the thoracic aorta of the male Dahl SS rat. The PVAT and aorta were physically separated for most assays. Results from single nuclei RNA sequencing (snRNAseq) experiments, histochemistry and isometric contractility were also used. Masson Trichrome staining made evident the expression of collagen in PVAT. From snRNA seq experiments of the PVAT, mRNA for multiple collagen and integrin isoforms were detected: the α1 and ß1 integrin were most highly expressed. Pharmacological inhibition of integrin/collagen interaction was effected by the specific α1ß1 distintegrin obtustatin or general integrin inhibitor RGD peptide. RGD peptide but not obtustatin increased the stress relaxation. Cell-cell communication inference identified integrins αv and α5, two major RGD motif containing isoforms, as potential signaling partners of collagens. Collectively, these findings validate that stress relaxation can occur in a non-smooth muscle tissue, doing so in part through integrin-collagen interactions that may not include α1ß1 heterodimers. The importance of this lies in considering PVAT as a vascular layer that possesses mechanical functions.

A cell atlas of thoracic aortic perivascular adipose tissue: a focus on mechanotransducers.

Perivascular adipose tissue (PVAT) is increasingly recognized for its function in mechanotransduction. However, major gaps remain in our understanding of the cells present in PVAT, as well as how different cells contribute to mechanotransduction. We hypothesized that snRNA-seq would reveal the expression of mechanotransducers, and test one (PIEZO1) to illustrate the expression and functional agreement between single-nuclei RNA sequencing (snRNA-seq) and physiological measurements. To contrast two brown tissues, subscapular brown adipose tissue (BAT) was also examined. We used snRNA-seq of the thoracic aorta PVAT (taPVAT) and BAT from male Dahl salt-sensitive (Dahl SS) rats to investigate cell-specific expression mechanotransducers. Localization and function of the mechanostransducer PIEZO1 were further examined using immunohistochemistry (IHC) and RNAscope, as well as pharmacological antagonism. Approximately 30,000 nuclei from taPVAT and BAT each were characterized by snRNA-seq, identifying eight major cell types expected and one unexpected (nuclei with oligodendrocyte marker genes). Cell-specific differential gene expression analysis between taPVAT and BAT identified up to 511 genes (adipocytes) with many (≥20%) being unique to individual cell types. Piezo1 was the most highly, widely expressed mechanotransducer. The presence of PIEZO1 in the PVAT but not the adventitia was confirmed by RNAscope and IHC in male and female rats. Importantly, antagonism of PIEZO1 by GsMTX4 impaired the PVAT's ability to hold tension. Collectively, the cell compositions of taPVAT and BAT are highly similar, and PIEZO1 is likely a mechanotransducer in taPVAT.NEW & NOTEWORTHY This study describes the atlas of cells in the thoracic aorta perivascular adipose tissue (taPVAT) of the Dahl-SS rat, an important hypertension model. We show that mechanotransducers are widely expressed in these cells. Moreover, PIEZO1 expression is shown to be restricted to the taPVAT and is functionally implicated in stress relaxation. These data will serve as the foundation for future studies investigating the role of taPVAT in this model of hypertensive disease.

Perivascular Adipose Tissue Remodels Only after Elevation of Blood Pressure in the Dahl SS Rat Fed a High-Fat Diet.

INTRODUCTION: Tunica media extracellular matrix (ECM) remodeling is well understood to occur in response to elevated blood pressure, unlike the remodeling of other tunicas. We hypothesize that perivascular adipose tissue (PVAT) is responsive to hypertension and remodels as a protective measure. METHODS: The adventitia and PVAT of the thoracic aorta were used in measuring ECM genes from 5 pairs of Dahl SS male rats on 8 or 24 weeks of feeding from weaning on a control (10% Kcal fat) or high-fat (HF; 60%) diet. A PCR array of ECM genes was performed with cDNA from adventitia and PVAT after 8 and 24 weeks. A gene regulatory network of the differentially expressed genes (DEGs) (HF 2-fold > con) was created using Cytoscape. RESULTS: After 8 weeks, 29 adventitia but 0 PVAT DEGs were found. By contrast, at 24 weeks, PVAT possessed 47 DEGs while adventitia had 3. Top DEGs at 8 weeks in adventitia were thrombospondin 1 and collagen 8a1. At 24 weeks, thrombospondin 1 was also a top DEG in PVAT. The transcription factor Adarb1 was identified as a regulator of DEGs in 8-week adventitia and 24-week PVAT. CONCLUSION: These data support that PVAT responds biologically once blood pressure is elevated.

A peer-volunteer led active ageing programme to prevent decline in physical function in older people at risk of mobility disability (Active, Connected, Engaged [ACE]): study protocol for a randomised controlled trial.

BACKGROUND: The Active Connected Engaged [ACE] study is a multi-centre, pragmatic, two-arm, parallel-group randomised controlled trial [RCT] with an internal pilot phase. The ACE study incorporates a multi-level mixed methods process evaluation including a systems mapping approach and an economic evaluation. ACE aims to test the effectiveness and cost-effectiveness of a peer-volunteer led active ageing intervention designed to support older adults at risk of mobility disability to become more physically and socially active within their communities and to reduce or reverse, the progression of functional limitations associated with ageing. METHODS/DESIGN: Community-dwelling, older adults aged 65 years and older (n = 515), at risk of mobility disability due to reduced lower limb physical functioning (Short Physical Performance Battery (SPPB) score of 4-9 inclusive) will be recruited. Participants will be randomised to receive either a minimal control intervention or ACE, a 6-month programme underpinned by behaviour change theory, whereby peer volunteers are paired with participants and offer them individually tailored support to engage them in local physical and social activities to improve lower limb mobility and increase their physical activity. Outcome data will be collected at baseline, 6, 12 and 18 months. The primary outcome analysis (difference in SPPB score at 18 months) will be undertaken blinded to group allocation. Primary comparative analyses will be on an intention-to-treat (ITT) basis with due emphasis placed on confidence intervals. DISCUSSION: ACE is the largest, pragmatic, community-based randomised controlled trial in the UK to target this high-risk segment of the older population by mobilising community resources (peer volunteers). A programme that can successfully engage this population in sufficient activity to improve strength, coordination, balance and social connections would have a major impact on sustaining health and independence. ACE is also the first study of its kind to conduct a full economic and comprehensive process evaluation of this type of community-based intervention. If effective and cost-effective, the ACE intervention has strong potential to be implemented widely in the UK and elsewhere. TRIAL REGISTRATION: ISRCTN, ISRCTN17660493. Registered on 30 September 2021. Trial Sponsor: University of Birmingham, Contact: Dr Birgit Whitman, Head of Research Governance and Integrity; Email: researchgovernance@contacts.bham.ac.uk. Protocol Version 5 22/07/22.

A Cell Atlas of Thoracic Aortic Perivascular Adipose Tissue: a focus on mechanotransducers.

Perivascular adipose tissue (PVAT) is increasingly recognized for its function in mechanotransduction. To examine the cell-specificity of recognized mechanotransducers we used single nuclei RNA sequencing (snRNAseq) of the thoracic aorta PVAT (taPVAT) from male Dahl SS rats compared to subscapular brown adipose tissue (BAT). Approximately 30,000 nuclei from taPVAT and BAT each were characterized by snRNAseq, identifying 8 major cell types expected and one unexpected (nuclei with oligodendrocyte marker genes). Cell-specific differential gene expression analysis between taPVAT and BAT identified up to 511 genes (adipocytes) with many (≥20%) being unique to individual cell types. Piezo1 was the most highly, widely expressed mechanotransducer. Presence of PIEZO1 in the PVAT was confirmed by RNAscope® and IHC; antagonism of PIEZO1 impaired the PVAT's ability to hold tension. Collectively, the cell compositions of taPVAT and BAT are highly similar, and PIEZO1 is likely a mechanotransducer in taPVAT.

The REtirement in ACTion exercise programme and its effects on elements of long term functionality in older adults.

Background: The prevention of mobility-related disability amongst adults is a global healthcare priority. Cost-effective community-based strategies to improve physical function and independence in older adults with mobility limitations are needed. This study investigated the effectiveness of the REtirement in ACTion (REACT) exercise intervention on individual markers of physical function at 6-and 12-months. Methods: The REACT multicentre randomised controlled trial assigned 777 older adults (female, 514; male 263) (mean age 77·6 [SD 6·8] years) with reduced lower limb physical functioning (Short Physical Performance Battery [SPPB] score 4-9) to receive brief healthy ageing advice or a 12-month, group-based, multimodal exercise programme delivered in local communities. Estimated differences in the three individual component scores of the SPPB (strength, balance, gait speed) and physical functional outcomes recorded at 6- and 12-months were assessed. Results: The intervention group demonstrated significant improvements in strength (OR = 1.88, 95% CI = 1.36-2.59, p < 0.001) and balance (OR = 1.96, 95% CI = 1.39-2.67, p < 0.001) at 12-months, but not in gait speed (OR = 1.32, 95% CI = 0.91-1.90, p = 0.139). In comparison to the control group, at six-and 12-months, the intervention group reported statistically significant improvements in Mobility Assessment Tool-Short Form (MAT-SF), physical component score from SF-36 questionnaire, and strength and endurance items of subjectively reported physical activity (PASE 10-item). Greater than 75% adherence (attending ≥48 of the 64 exercise sessions delivered in 12-months) was associated with superior functional outcomes. Conclusion: The REACT exercise programme provides local, regional and national service providers with an effective solution to increase muscle strength and balance in older adults at risk of mobility disability.

Chemerin is resident to vascular tunicas and contributes to vascular tone.

The adipokine chemerin may support blood pressure, evidenced by a fall in mean arterial pressure after whole body antisense oligonucleotide (ASO)-mediated knockdown of chemerin protein in rat models of normal and elevated blood pressure. Although the liver is the greatest contributor of circulating chemerin, liver-specific ASOs that abolished hepatic-derived chemerin did not change blood pressure. Thus, other sites must produce the chemerin that supports blood pressure. We hypothesize that the vasculature is a source of chemerin independent of the liver that supports arterial tone. RNAScope, PCR, Western blot analyses, ASOs, isometric contractility, and radiotelemetry were used in the Dahl salt-sensitive (SS) rat (male and female) on a normal diet. Retinoic acid receptor responder 2 (Rarres2) mRNA was detected in the smooth muscle, adventitia, and perivascular adipose tissue of the thoracic aorta. Chemerin protein was detected immunohistochemically in the endothelium, smooth muscle cells, adventitia, and perivascular adipose tissue. Chemerin colocalized with the vascular smooth muscle marker α-actin and the adipocyte marker perilipin. Importantly, chemerin protein in the thoracic aorta was not reduced when liver-derived chemerin was abolished by a liver-specific ASO against chemerin. Chemerin protein was similarly absent in arteries from a newly created global chemerin knockout in Dahl SS rats. Inhibition of the receptor Chemerin1 by the receptor antagonist CCX832 resulted in the loss of vascular tone that supports potential contributions of chemerin by both perivascular adipose tissue and the media. These data suggest that vessel-derived chemerin may support vascular tone locally through constitutive activation of Chemerin1. This posits chemerin as a potential therapeutic target in blood pressure regulation.NEW & NOTEWORTHY Vascular tunicas synthesizing chemerin is a new finding. Vascular chemerin is independent of hepatic-derived chemerin. Vasculature from both males and females have resident chemerin. Chemerin1 receptor activity supports vascular tone.

5-HT7 receptors mediate dilation of rat cremaster muscle arterioles in vivo.

OBJECTIVE: Serotonin (5-HT) infusion in vivo causes hypotension and a fall in total peripheral resistance. However, the vascular segment and the receptors that mediate this response remain in question. We hypothesized that 5-HT7 receptors mediate arteriolar dilation to 5-HT in skeletal muscle microcirculation. METHODS: Cremaster muscles of isoflurane-anesthetized male Sprague-Dawley rats were prepared for in vivo microscopy of third- and fourth-order arterioles and superfused with physiological salt solution at 34°C. Quantitative real-time PCR (RT-PCR) was applied to pooled samples of first- to third-order cremaster arterioles (2-4 rats/sample) to evaluate 5-HT7 receptor expression. RESULTS: Topical 5-HT (1-10 nmols) or the 5-HT1/7 receptor agonist, 5-carboxamidotryptamine (10-30 nM), dilated third- and fourth-order arterioles, responses that were abolished by 1 µM SB269970, a selective 5-HT7 receptor antagonist. In contrast, dilation induced by the muscarinic agonist, methacholine (100 nmols) was not inhibited by SB269970. Serotonin (10 nmols) failed to dilate cremaster arterioles in 5-HT7 receptor knockout rats whereas arterioles in wild-type litter mates dilated to 1 nmol 5-HT, a response blocked by 1 µM SB269970. Quantitative RT-PCR revealed that cremaster arterioles expressed mRNA for 5-HT7 receptors. CONCLUSIONS: 5-HT7 receptors mediate dilation of small arterioles in skeletal muscle and likely contribute to 5-HT-induced hypotension, in vivo.

Development of a 5-HT7 receptor antibody for the rat: the good, the bad, and the ugly.

Our laboratory has a vested interest in measuring the location and expression of the 5-hydroxytryptamine (5-HT, serotonin) 7 (5-HT7) receptor in the rat. Determining tissue-specific receptor expression would aid in validating understood and potentially new tissues that support the 5-HT7 receptor-mediated fall in blood pressure, an event we are committed to understand. We contracted with 7TM Antibodies to develop deliberately and rigorously a rat 5-HT7 (r5-HT7) receptor specific antibody. Three antigens, two targeting the third internal loop and one the C terminus, were used in three rabbits to generate antibodies. As a positive control, HEK293(T or AD) cells were transfected with a plasmid for the r5-HT7 receptor also expressing a C terminus 3xFLAG tag. Naïve rat tissues were also used in Western and immunohistochemical analyses. Nine antibodies (3 from three different rabbits) detected a ~ 75 kDa protein absent in homogenates of vector control HEK293T cells. Only antibodies that recognized the C terminus of the 5-HT7 receptor [ERPERSEFVLQNSDH(Abu)GKKGHDT; antibodies 3, 6, and 9] positively and concentration-dependently identified the r5-HT7 receptor expressed in Westerns of transfected HEK293T cells. These same C terminus antibodies also successfully detected the r5-HT7 receptor in immunocytochemical test of the transfected HEK293AD cells, colocalizing with the detected FLAG sequence. In naive tissue, antibody 6 performed the best, identifying specific bands in the brain cortex in Western analysis. These same antibodies produced a more diverse band profile in the vena cava, identifying 6 major proteins. In immunohistochemical experiments, the same C-terminus antibodies, with antibody 3 performing the best, detected the 5-HT7 receptor in rat veins. This deliberate work has given rise to at least three antibodies that can be used with good confidence in r5-HT7 transfected cells, two antibodies that can be used in immunohistochemical analyses of rat tissues and in Westerns of rat brain; we are less confident of the use of these same antibodies in rat veins.

Risk of food insecurity in undocumented migrant households in Birmingham, UK.

BACKGROUND: This study aimed to understand the extent of household food insecurity amongst undocumented migrant families in Birmingham,UK. METHODS: Cross-sectional survey of households (n = 74) with dependent children using the USDA 18-item household food security (HFS) module. All households had an irregular immigration status and were accessing an immigration advice drop-in service (n = 98 adults; n = 138 children) in Birmingham. RESULTS: About 95.9% of households were food insecure, and 94.6% of children lived in households with low or very low food security. Food insecurity varied within households. Around 91.8% of adults were food insecure, compared to 75.6% of children. Spearman's rank-order correlation indicated a statistically significant positive correlation between household food insecurity level and number of children (rho = 0.253, P = 0.031). A Kruskal-Wallis H Test indicated no statistically significant difference (P = 0.730) in HFS score between households supported by asylum support, children's social services or paid employment in the informal economy and those that had no regular income. CONCLUSIONS: Prevalence of HFS was higher in this sample of undocumented migrant households with dependent children in Birmingham, UK, than in the wider population, and larger households were more food insecure. Households without a regular income were no more likely to be food insecure than households with financial support.

Knowledge of Nutrition and Physical Activity Guidelines is Not Associated with Physical Function in Dutch Older Adults Attending a Healthy Ageing Public Engagement Event.

Purpose: Evidence-based guidelines on nutrition and physical activity are used to increase knowledge in order to promote a healthy lifestyle. However, actual knowledge of guidelines is limited and whether it is associated with health outcomes is unclear. Participants and Methods: This inception cohort study aimed to investigate the association of knowledge of nutrition and physical activity guidelines with objective measures of physical function and physical activity in community-dwelling older adults attending a public engagement event in Amsterdam, The Netherlands. Knowledge of nutrition and physical activity according to Dutch guidelines was assessed using customized questionnaires. Gait speed and handgrip strength were proxies of physical function and the Minnesota Leisure Time Physical Activity Questionnaire was used to assess physical activity in minutes/week. Linear regression analysis, stratified by gender and adjusted for age, was used to study the association between continuous and categorical knowledge scores with outcomes. Results: In 106 older adults (mean age=70.1 SD=6.6, years) who were highly educated, well-functioning, and generally healthy, there were distinct knowledge gaps in nutrition and physical activity which did not correlate with one another (R2=0.013, p=0.245). Knowledge of nutrition or physical activity guidelines was not associated with physical function or physical activity. However, before age-adjustment nutrition knowledge was positively associated with HGS in males (B= 0.64 (95% CI: 0.05, 1.22)) and having knowledge above the median was associated with faster gait speed in females (B=0.10 (95% CI: 0.01, 0.19)). Conclusion: Our findings may represent a ceiling effect of the impact knowledge has on physical function and activity in the this high performing and educated population and that there may be other determinants of behavior leading to health status such as attitude and perception to consider in future studies.

PIEZO1 mechanoreceptor activation reduces adipogenesis in perivascular adipose tissue preadipocytes.

During hypertension, vascular remodeling allows the blood vessel to withstand mechanical forces induced by high blood pressure (BP). This process is well characterized in the media and intima layers of the vessel but not in the perivascular adipose tissue (PVAT). In PVAT, there is evidence for fibrosis development during hypertension; however, PVAT remodeling is poorly understood. In non-PVAT depots, mechanical forces can affect adipogenesis and lipogenic stages in preadipocytes. In tissues exposed to high magnitudes of pressure like bone, the activation of the mechanosensor PIEZO1 induces differentiation of progenitor cells towards osteogenic lineages. PVAT's anatomical location continuously exposes it to forces generated by blood flow that could affect adipogenesis in normotensive and hypertensive states. In this study, we hypothesize that activation of PIEZO1 reduces adipogenesis in PVAT preadipocytes. The hypothesis was tested using pharmacological and mechanical activation of PIEZO1. Thoracic aorta PVAT (APVAT) was collected from 10-wk old male SD rats (n=15) to harvest preadipocytes that were differentiated to adipocytes in the presence of the PIEZO1 agonist Yoda1 (10 µM). Mechanical stretch was applied with the FlexCell System at 12% elongation, half-sine at 1 Hz simultaneously during the 4 d of adipogenesis (MS+, mechanical force applied; MS-, no mechanical force used). Yoda1 reduced adipogenesis by 33% compared with CON and, as expected, increased cytoplasmic Ca2+ flux. MS+ reduced adipogenesis efficiency compared with MS-. When Piezo1 expression was blocked with siRNA [siPiezo1; NC=non-coding siRNA], the anti-adipogenic effect of Yoda1 was reversed in siPiezo1 cells but not in NC; in contrast, siPiezo1 did not alter the inhibitory effect of MS+ on adipogenesis. These data demonstrate that PIEZO1 activation in PVAT reduces adipogenesis and lipogenesis and provides initial evidence for an adaptive response to excessive mechanical forces in PVAT during hypertension.

Is the 5-hydroxytryptamine 7 Receptor Constitutively Active in the Vasculature? A Study in Veins/Vein.

ABSTRACT: The 5-hydroxytryptamine 7 (5-HT 7 ) receptor is reported to have considerable constitutive activity when transfected into cells. Constitutive activity-receptor activity in the absence of known agonist-is important for understanding the contributions of a receptor to (patho)physiology. We test the hypothesis that the 5-HT 7 receptor possesses constitutive activity in a physiological situation. Isolated veins from male and female Sprague Dawley rats were used as models for measuring isometric force; the abdominal vena cava possesses a functional 5-HT 7 receptor that mediates relaxation, whereas the small mesenteric vein does not. Compounds reported to act as inverse agonists were investigated for their ability to cause contraction (moving a constitutively active relaxant receptor to an inactive state, removing relaxation). Compared with a vehicle control, clozapine, risperidone, ketanserin, and SB269970 caused no contraction in the isolated male abdominal vena cava. By contrast, methiothepin caused a concentration-dependent contraction of the male but not female abdominal vena cava, although with low potency (-log EC 50 [M] = 5.50 ± 0.45) and efficacy (∼12% of contraction to endothelin-1). Methiothepin-induced contraction was not reduced by the 5-HT 7 receptor antagonist (SB269970, 1 µM, not active in the vena cava). These same compounds showed little to no effect in the isolated mesenteric vein. We conclude that the 5-HT 7 receptor in the isolated veins of the Sprague Dawley rat does not possess constitutive activity. We raise the question of the physiological relevance of constitutive activity of this receptor important to such diverse physiological functions as sleep, circadian rhythm, temperature, and blood pressure regulation.

Assessing the fidelity of delivery style of a mental skills training programme for young people experiencing homelessness.

There is a need for positive youth development/strengths-based approaches to support the wellbeing and social inclusion of young people experiencing or at risk of homelessness. My Strengths Training for Life™ (MST4Life™) uses a strengths-based approach with the aim to improve young people's resilience, self-worth, wellbeing and engagement in education, employment, and training. This mixed methods study assessed the fidelity of delivery style of the MST4Life™ programme, the extent to which frontline service staff can delivery psychologically informed programmes to service users and identified barriers and enablers to delivering with fidelity to the intended style. Observations of programme delivery (two facilitators per session) took place across early, middle, and late phases of the programme across a pilot phase (n = 18) and main study (n = 45). Facilitators also completed self-reflection forms following each session. The mean observation score was 82.2 ± 15.7 %, and facilitator self-report mean adherence score was 89.3 ± 6.2 % which indicate that the programme was delivered with high fidelity. Quantitative data was also analysed using non-parametric statistical test (Mann-Whitney U Test). There was a significant difference between observation scores for deliverers with postgraduate psychology training compared to deliverers without postgraduate psychology training (p = .029). Qualitative data were analysed using inductive thematic analysis. Barriers and enablers included communication, frontline staff support, logistics, and participant behaviours. Overall, this study highlights that despite the challenges of delivering complex community programmes to young people experiencing homelessness, it was possible for frontline service staff to deliver MST4Life™ with high fidelity.

The Physical Activity and Nutritional INfluences in Ageing (PANINI) Toolkit: A Standardized Approach towards Physical Activity and Nutritional Assessment of Older Adults.

Assessing multiple domains of health in older adults requires multidimensional and large datasets. Consensus on definitions, measurement protocols and outcome measures is a prerequisite. The Physical Activity and Nutritional INfluences In Ageing (PANINI) Toolkit aims to provide a standardized toolkit of best-practice measures for assessing health domains of older adults with an emphasis on nutrition and physical activity. The toolkit was drafted by consensus of multidisciplinary and pan-European experts on ageing to standardize research initiatives in diverse populations within the PANINI consortium. Domains within the PANINI Toolkit include socio-demographics, general health, nutrition, physical activity and physical performance and psychological and cognitive health. Implementation across various countries, settings and ageing populations has proven the feasibility of its use in research. This multidimensional and standardized approach supports interoperability and re-use of data, which is needed to optimize the coordination of research efforts, increase generalizability of findings and ultimately address the challenges of ageing.

Cost-effectiveness of a physical activity and behaviour maintenance programme on functional mobility decline in older adults: an economic evaluation of the REACT (Retirement in Action) trial.

BACKGROUND: Mobility limitations in older populations have a substantial impact on health outcomes, quality of life, and social care costs. The Retirement in Action (REACT) randomised controlled trial assessed a 12-month community-based group physical activity and behaviour maintenance intervention to help prevent decline in physical functioning in older adults at increased risk of mobility limitation. We aimed to do an economic evaluation of the REACT trial to investigate whether the intervention is cost-effective. METHODS: In this health economic evaluation, we did cost-effectiveness and cost-utility analyses of the REACT programme versus standard care on the basis of resource use, primary outcome, and health-related quality-of-life data measured in the REACT trial. We also developed a decision analytic Markov model that forecasts the mobility of recipients beyond the 24-month follow-up of the trial and translated this into future costs and potential benefit to health-related quality of life using the National Health Service and Personal Social Services perspective. Participants completed questionnaire booklets at baseline, and at 6, 12, and 24 months after randomisation, which included a resource use questionnaire and the EQ-5D-5L and 36-item short-form survey (SF-36) health-related quality-of-life instruments. The cost of delivering the intervention was estimated by identifying key resources, such as REACT session leader time, time of an individual to coordinate the programme, and venue hire. EQ-5D-5L and SF-36 responses were converted to preference-based utility values, which were used to estimate quality-adjusted life-years (QALYs) over the 24-month trial follow-up using the area-under-the-curve method. We used generalised linear models to examine the effect of the REACT programme on costs and QALYs and adjust for baseline covariates. Costs and QALYs beyond 12 months were discounted at 3·5% per year. This is a pre-planned analysis of the REACT trial; the trial itself is registered with ISRCTN (ISRCTN45627165). FINDINGS: The 12-month REACT programme was estimated to cost £622 per recipient to deliver. The most substantial cost components are the REACT session leader time (£309 per participant), venue hire (£109), and the REACT coordinator time (£80). The base-case analysis of the trial-based economic evaluation showed that reductions in health and social care usage due to the REACT programme could offset the REACT delivery costs (£3943 in the intervention group vs £4043 in the control group; difference: -£103 [95% CI -£695 to £489]) with a health benefit of 0·04 QALYs (0·009-0·071; 1·354 QALYs in the intervention group vs 1·314 QALYs in the control group) within the 24-month timeframe of the trial. INTERPRETATION: The REACT programme could be considered a cost-effective approach for improving the health-related quality of life of older adults at risk of mobility limitations. FUNDING: National Institute for Health Research Public Health Research Programme.

Effect of a physical activity and behaviour maintenance programme on functional mobility decline in older adults: the REACT (Retirement in Action) randomised controlled trial.

BACKGROUND: Mobility limitations in old age can greatly reduce quality of life, generate substantial health and social care costs, and increase mortality. Through the Retirement in Action (REACT) trial, we aimed to establish whether a community-based active ageing intervention could prevent decline in lower limb physical functioning in older adults already at increased risk of mobility limitation. METHODS: In this pragmatic, multicentre, two-arm, single-blind, parallel-group, randomised, controlled trial, we recruited older adults (aged 65 years or older and who are not in full-time employment) with reduced lower limb physical functioning (Short Physical Performance Battery [SPPB] score 4-9) from 35 primary care practices across three sites (Bristol and Bath; Birmingham; and Devon) in England. Participants were randomly assigned to receive brief advice (three healthy ageing education sessions) or a 12-month, group-based, multimodal physical activity (64 1-h exercise sessions) and behavioural maintenance (21 45-min sessions) programme delivered by charity and community or leisure centre staff in local communities. Randomisation was stratified by site and adopted a minimisation approach to balance groups by age, sex, and SPPB score, using a centralised, online, randomisation algorithm. Researchers involved in data collection and analysis were masked but participants were not because of the nature of the intervention. The primary outcome was change in SPPB score at 24 months, analysed by intention to treat. This trial is registered with ISRCTN, ISRCTN45627165. FINDINGS: Between June 20, 2016, and Oct 30, 2017, 777 participants (mean age 77·6 [SD 6·8] years; 66% female; mean SPPB score 7·37 [1·56]) were randomly assigned to the intervention (n=410) and control (n=367) groups. Primary outcome data at 24 months were provided by 628 (81%) participants (294 in the control group and 334 in the intervention group). At the 24-month follow-up, the SPPB score (adjusted for baseline SPPB score, age, sex, study site, and exercise group) was significantly greater in the intervention group (mean 8·08 [SD 2·87]) than in the control group (mean 7·59 [2·61]), with an adjusted mean difference of 0·49 (95% CI 0·06-0·92; p=0·014), which is just below our predefined clinically meaningful difference of 0·50. One adverse event was related to the intervention; the most common unrelated adverse events were heart conditions, strokes, and falls. INTERPRETATION: For older adults at risk of mobility limitations, the REACT intervention showed that a 12-month physical activity and behavioural maintenance programme could help prevent decline in physical function over a 24-month period. FUNDING: National Institute for Health Research Public Health Research Programme (13/164/51).

Identification of Piezo1 channels in perivascular adipose tissue (PVAT) and their potential role in vascular function.

The vasculature constantly experiences distension/pressure exerted by blood flow and responds to maintain homeostasis. We hypothesized that activation of the stretch sensitive, non-selective cation channel Piezo1 would directly increase vascular contraction in a way that might be modified by perivascular adipose tissue (PVAT). The presence and function of Piezo1 was investigated by RT-PCR, immunohistochemistry, and isolated tissue bath contractility. Superior and mesenteric resistance arteries, aortae, and their PVATs from male Sprague Dawley rats were used. Piezo1 mRNA was detected in aortic vessels, aortic PVAT, mesenteric vessels, and mesenteric PVAT. Both adipocytes and stromal vascular fraction of mesenteric PVAT expressed Piezo1 mRNA. In PVAT, expression of Piezo1 mRNA was greater in magnitude than that of Piezo2, transient receptor potential cation channel, subfamily V, member 4 (TRPV4), anoctamin 1, calcium activated chloride channel (TMEM16), and Pannexin1 (Panx1). Piezo1 protein was present in endothelium and PVAT of rat aortic and in PVAT of mesenteric artery. The Piezo1 agonists Yoda1 and Jedi2 (1 nM - 10 µM) did not stimulate aortic contraction [max < 10% phenylephrine (PE) 10 µM contraction] or relaxation in tissues + or -PVAT. Depolarizing the aorta by modestly elevated extracellular K+ did not unmask aortic contraction to Yoda1 (max <10% PE 10 µM contraction). Finally, the Piezo1 antagonist Dooku1 did not modify PE-induced aorta contraction + or -PVAT. Surprisingly, Dooku1 directly caused aortic contraction in the absence (Dooku1 =26 ± 11; Vehicle = 11 ± 11%PE contraction) but not in the presence of PVAT (Dooku1 = 2 ± 1; Vehicle = 8 ± 5% PE contraction). Thus, Piezo1 is present and functional in the isolated rat aorta but does not serve direct vascular contraction with or without PVAT. We reaffirmed the isolated mouse aorta relaxation to Yoda1, indicating a species difference in Piezo1 activity between mouse and rat.

Social media use informing behaviours related to physical activity, diet and quality of life during COVID-19: a mixed methods study.

BACKGROUND: This mixed methods study explored how social media use informed physical activity and diet-related behaviours, and self-perceived Quality of Life (QoL) during COVID-19, and assessed the contextual factors that drive social media use for health-related behaviour change in diverse groups. During the COVID-19 lockdown periods there were reported changes to social media use and health behaviours, and this gave an opportunity to investigate potential relationships. METHODS: An explanatory sequential research design of two parts was used: (1) An online survey that assessed social media use in relation to physical activity levels, diet quality and QoL (n = 786; Mage 45.1 ± 19.1 (range 16-88) years; Female =69%); (2) 20 purposive focus groups (n = 69; Mage = 52.88 ± 18.45 years, Female n = 68%) to understand the contextual factors that drive social media use for health-related behaviour change. Descriptive and thematic analysis were conducted. RESULTS: Participants in this study reported that social media facilitated the self-management of behaviours related to physical activity, diet and QoL, through access to information to inform workouts and dietary quality, and the opportunities for interaction with peers, family members and within social groups. Contextual factors including work, home and lifestyle arrangements, pre-existing health-related knowledge and behaviours, and the perceived value of social media for health influenced the relationship between social media use and self-reported outcomes. Social media influencers, peers/family members, and official organisations influenced the application of health-related information accessed via social media. CONCLUSIONS: The evidence shows that participants were critical users of social media and were able to use social media to derive benefit for their health and wellbeing. Detailed guidance for those who use social media, as well as those who recommend and endorse social media content is required to maximise the potential of social media to support health behaviours. Future public health strategies and social media interventions should acknowledge diversity in contextual factors driving social media use for health behaviour change.

The effect of social media interventions on physical activity and dietary behaviours in young people and adults: a systematic review.

BACKGROUND: The objectives of this systematic review were to update the evidence base on social media interventions for physical activity and diet since 2014, analyse the characteristics of interventions that resulted in changes to physical activity and diet-related behaviours, and assess differences in outcomes across different population groups. METHODS: A systematic search of the literature was conducted across 5 databases (Medline, Embase, EBSCO Education, Wiley and Scopus) using key words related to social media, physical activity, diet, and age. The inclusion criteria were: participants age 13+ years in the general population; an intervention that used commercial social media platform(s); outcomes related to changes to diet/eating or physical activity behaviours; and quantitative, qualitative and mixed methods studies. Quality appraisal tools that aligned with the study designs were used. A mixed methods approach was used to analyse and synthesise all evidence. RESULTS: Eighteen studies were included: randomised control trials (n = 4), non-controlled trials (n = 3), mixed methods studies (n = 3), non-randomised controlled trials (n = 5) and cross-sectional studies (n = 3). The target population of most studies was young female adults (aged 18-35) attending college/university. The interventions reported on positive changes to physical activity and diet-related behaviours through increases in physical activity levels and modifications to food intake, body composition and/or body weight. The use of Facebook, Facebook groups and the accessibility of information and interaction were the main characteristics of social media interventions. Studies also reported on Instagram, Reddit, WeChat and Twitter and the use of photo sharing and editing, groups and sub-groups and gamification. CONCLUSIONS: Social media interventions can positively change physical activity and diet-related behaviours, via increases in physical activity levels, healthy modifications to food intake, and beneficial changes to body composition or body weight. New evidence is provided on the contemporary uses of social media (e.g. gamification, multi-model application, image sharing/editing, group chats) that can be used by policy makers, professionals, organisations and/or researchers to inform the design of future social media interventions. This study had some limitations that mainly relate to variation in study design, over-reliance of self-reported measures and sample characteristics, that prevented comparative analysis. Registration number: PROPSERO; CRD42020210806 .